This summary describes the collection of necessary tutorials to host strapy on your uberspace
just follow this well written tutorial.
take just a segment of this tutorial. be sure to use the before defined credentials (like, ip address, port, username e.g. of your freshly created database)
just follow this tutorial
a list of detailed steps can be found here
Your cms should be now available under https://subdomain.yourdomain.com/admin
In case anybody is reading this, you need node 14 to run strapi on uberspace.
uberspace tools version use node 14
Also, use this for bullet point 4.
uberspace web backend set api.domain.com --http --port 1337
The rest can be followed from the notes above.