++SankoR has shown a quote regarding use_ok from Test2::Bundle::More. You'd do well to read all of that page; in particular the sections "KEY DIFFERENCES FROM Test::More" and "THESE FUNCTIONS AND VARIABLES HAVE BEEN REMOVED".

You don't show any code using use_ok. The code examples from Test::More::use_ok generally have this form:

BEGIN { use_ok('Some::Module') }
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You could change whatever lines you have like that to

use ok 'Some::Module';
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Note there's no underscore between use and ok. This will work under Test2::V0. See the core module ok for more on that.

"... moving to 5.38.2 (don't ask :)"

I'd expect Perl v5.40.0 to be released in the next couple of months or so. Test2::Suite should become a core module in that version: see "perldelta (for 5.39.4): New Modules and Pragmata". You obviously have a lot of work to do with this conversion: I won't ask why v5.38.2 but maybe v5.40.0 might be a better target as you won't need to download and install various Test2::* modules from CPAN.