Retrofit windows in prefabricated garage

Hello,

I bought a house that comes with 2 prefabricated garages. One of them has a standard garage door, the other only a regular entrance door and was used as a storage room since there is no basement. The one without a door will be my workshop, but I want to retrofit a window where there would normally be a door. How is it with the statics of these prefabricated garages? Can/may I just cut a hole for a window (approx. 90x90 cm) and install it?

Thank you very much in advance!

Best regards

We have a draft garage, and retrofitting a window shall not be possible.

Alternative: install a door with a window cutout.