One word of caution: at least if you're based in the EU, this is basically impossible to do legally correctly by yourself globally unless you spend many thousands of dollars VAT-registering yourself in all kinds of places around the world and knowing global tax laws to make sure you get everything right, since electronically delivered goods (like your SaaS) are taxed in the country of the recipient of the services. Within the EU it's at least possible to use a simplified MOSS (mini one stop shop) process, but that also has its drawbacks.

This is the best summary I found of the situation so far: https://quaderno.io/resources/eu-vat-guide/

Basically I arrived at the conclusion that it's impossible for me as a small business to do global B2C VAT (not just calculation, but also actual remittance) myself, and thus am using resellers (Copecart, Digistore24, Paddle, FastSpring) that do all this for you by being a complete middleman in the transaction. Of course they then also take a larger cut than something more light-weight like Stripe. I wish Stripe also supported global VAT / sales tax remittance.

EDIT: See also https://www.youtube.com/watch?v=MowACIitd1s and https://www.youtube.com/watch?v=sO4nzWWMAvg