Can’t speak for where you live but if the optician is being a, excuse the expression, little bitch about it then that is poor behaviour on their part. I have never heard of an optician refusing to hand out the measurements here.
On a slightly related note: Opticians often get the glasses made elsewhere and simply install them into the frames (at huge markup), you could try locating a glass supplier and have your glasses made by them directly (saves you a bunch of money, speaking from experience). Assuming they offer individual glasses of course.
I’ll be that guy: Use forgejo instead, its main contributor is a Non-Profit compared to Gitea’s For-Profit owners