You are killing it over text. Calling her randomly isn’t a bad technique. If she doesn’t answer you try shooting over a message like “tag your it” or “hey just called”, then maybe “driving home if you have a moment.”
Girls aren’t used to a guy just calling so they might get nervous, and
most people don’t just pick up their phones anymore.
This is how you normalize it and then relieve any negative tension with the follow up text. She might call you back, or she might text you “hey, I can’t talk right now.”
Don’t get discouraged you can always respond with something along the lines of “all good. I wanted to set something up for later this week. What day are you free? (And text me later if you are busy right now)”
So, to recap she probably won’t answer when you call randomly, which is fine, you can use this opportunity to springboard into a close.
And if she doesn’t respond right away, then balls in her court to reopen you.
Best Regards
-Paul