Sending email from App - I get Suspicious sign in prevented

I have this phone app with a feature to send the internal logs using email, Users of this app are all over the world.

I configured a new gmail account with "Less secure app access" enabled on the account

but still getting "Suspicious sign in prevented" all the time, preventing users from sending emails. I suspect its due to the different geographic locations?
Or maybe I designed it wrong?
what is the correct way to send an email from WebApplication / app with different geographic locations?

Thank you!