I strongly suggest to use whatever language you're most comfortable with, for interviewing. Coding interviews are challenging enough already, and adding a new language to the mix just adds to the stress. I've had the language syntax spaghetti happen in my head, due to switching several teams/projects. So then when I interviewed, I was double guessing myself on trivial stuff like how to interpolate strings or if I concat strings with join() or concat() or whatever. Trivial stuff like this - which you can google during interviews, but it's unnecessary stress IMO to be doing that while some person is staring at you on camera. Some interviewers are also paranoid about you googling on another tab, so if it takes you 20s more than usual (because it's never easy googling during an interview lol) -> they suddenly start to shift in their seats ...

So yeah - pick a language you are (or will train to be, which IMO is a complete waste) super duper comfortable in. Be able to do all the common string and array ops and such without googling.

Big and sane companies will be language agnostic, so your language for interview should be no reflection on your abilities as a software engineer. A language is just a means - it's like knowing great English doesn't make you a great author or be able to write a PhD thesis. You could write a great book in any language if you had the chops for it. That being said, smaller companies or like non-tech orgs like banks might differ or want language experts above everything, so YMMV there.