The only flaw would be that
_ is not a Google-recommended separator for filenames. Unless there are technical reasons to use
_, it is better to use
This has historical reasons and Google employees have been unclear on weather
_ is now equal to
- or not. So bets practice is to stick with
Also, if you expect to have multiple pages in both English and Turkish, using subdirectories would be cleaner:
/tr/example.php. Or in your case, you could simply add
/en/ as a subdirectory for English content and leave the rest of the site as it is.
"Cleaner", in this case, means it is easier for Google to understand that one part of your website is English and another Turkish. It also makes it easier for you to segment the data in Google Search Console, Google Analytics, and virtually any other tool.
Edit: To clarify, if you want to rank in both languages, you must have a separate URL (page) for each language. You cannot have both languages on the URL (page).