Goal conversions are only counted once per goal per session, at the first time the action that the goal is tracking happens. There is no way to change that; goal conversions are determined by Google Analytics internally from the data it receives.
There are, then, two ways to get multiple conversions into the goal report: when you have multiple conversions per session, either separate them into different goals or into different sessions. That is, make separate events/goals for repetitions of the event, or force-trigger new sessions upon repetition of the event. Both have potential negative consequences, so I encourage you to think about what you are trying to accomplish by getting multiple conversions into goals. Could you use event reporting to get your totals, for example?
The "separate event" setup would look like this: you haven't said what you are tracking exactly, so let's suppose it's submission of comments. Instead of an event that has Category / Action / Label as follows:
Salesforce / Customer Contact / Comment Submitted
you would instead have multiple events that look as follows:
Salesforce / Customer Contact / First Comment Submitted
Salesforce / Customer Contact / Second Comment Submitted
And so forth. Then instead of one goal, you would have a goal that tracks the first event, one for the second event, and on for however many events you have.
There are three clear limitations on this:
- there must be a small upper bound on the number of times a visitor will perform the action
- you must be able to label the events accurately on the Salesforce end
- you must have enough available goals to track each of the events
The downside to that approach is that it complicates things: you're no longer looking at a single event and goal. However, if you set it up so that the Category and Action are the same for every repetition of the event, and only the Label differs, your event reporting should be just as easily used as before.
The second approach is to trigger a new session. Just remember this will affect all of your GA data, disconnecting user actions that in reality took place within a single session. If the only thing you care about is events, that is probably fine - but if the only thing you care about is events, I would again ask whether goals are necessary to get the data you need.
The easy but extreme method is to decrease the Google Analytics session timeout setting to its minimum, 1 minute. This setting is found in your GA Admin > Property > Tracking Info > Session Settings. If hits happened to arrive less than 1 minute apart, they would be counted as in the same session, but otherwise they would be in different sessions.
The other way to trigger a new session is with UTM parameters. You would have to add distinct parameters to the event hit (I am not a Measurement Protocol expert, but I believe that is allowed; if that doesn't work you would have to precede each event hit with a pageview hit that had the parameters attached). That event would then count as the first hit of the new session.
Again, this cuts apart your session data, and information such as attribution of conversions to the correct Source and Medium will be lost. That is, unless you can maintain that information in the code that sends the data to GA and send the correct Source and Medium, and perhaps a distinct Campaign (it would still trigger a different session, but the attribution would be correct). You've indicated this would likely be unreliable, as well as not reflect the reality (events are in the same session because they are by the same user), so I'm just including it for completeness.
If neither of the approaches above works, then goals can't do what you want.
Getting What You Need From Event Reports
If you want the goal reporting in standard reports because you are interested in the attribution and audience for your event, you can add those dimensions as secondary dimensions to the events report.
If you have enough data to be subject to sampling, this will trigger sampling, but that can be mitigated by using a small date range. You may also have to do some calculation, if you are interested in which channels (etc) produce the most events proportional to their session count.
If I were reporting on this for my own company, it sounds like a situation where I would turn to external tools, such as the GA add-on for Google Sheets. I have a lengthy recent answer about ways to mitigate sampling, including the Sheets add-on, if that seems like a direction you want to explore.