You'll want to look around for various IBM, Microsoft, and 3rd-party "basic" compilers/interpreters/etc ... if you search this forum, you'll find links where folks talk about some of these, like:
https://www.os2world.com/forum/index.php/topic,1446.0.html (reply 23 looks interesting)
And then, various google searches for OS/2 dev tools and apps, such as:
https://www.os2site.com/sw/dev/basic/index.htmlNote that many of these are for older versions of OS/2, so who knows how they'll run under ArcaOS or whatever OS/2 you've got running. Perhaps BASIC programmers who also use ArcaOS will chime in, and give their input on the best thing to run these days, on a "modern" ArcaOS.
Hope this helps ...