What to talk on calls when both M24 and F23 are introverts ?

Hi, I(M24) met a girl(F23) on a dating platform and we instantly vibed, and we chatted alot on there now on Insta and WP, and we also went on a date once and it was good and it's been 3 months and we both are looking for something serious. But now the issue is we both are introverts and I like to chat or else meet in person and explore places etc. But she's asking that we should talk on calls not via chat, but whenever we're on a call I get blank and don't know what to talk about and it's get's awkwardly silent.

What shall I do in this, I have always been accompanied by Extroverts so I never felt this way.