Usually IPA is labeled with the % alcohol it contains (e.g. 99%, 91%, 90%, 70%, etc). Formlabs recommends 90% or higher. They used to recommend even higher, but backed off as apparently lower concentration is safer to handle as a household chemical. I’ve also been told 99% eventually evaporates down to 90% dilution anyway when not sealed.
Personally I find it most cost effective to buy 99%, and mix it with distilled water to dilute down to 90%. I keep some 99% in a bottle for spot work.
“Medical” grade alcohol that isn’t otherwise labeled might be only 70%. I’m not sure about “technical”.
Locally, I’ve heard supply distributors for the film industry still have some gallons of IPA in stock (propmakers, etc) as the film industry is largely shut down.
EDIT: TPM is an alternative that may be easier to source right now.
Good luck!