either exporting sms text messages directtly to a txt document from iOS without an iMazing or iTunes backup?

Hi,
I'm trying to export a BUNCH (over 15000) sms messages to a .txt document. I have a 1 tb iPhone, so backing up to itunes isn't feasible, I don't have that much drive space. Is there a mac app that will let me export these texts? I did try an app that exported texts to a .db (database) file, but I can't get that to go into a .txt file. Any help would be much appreciated, as I'd love to have these texts.