I want to use the Raspberry Pi Zero W as an embedded controller for a device that a third party could use by configuring WiFi connection via USB or hot spot, like you would configure a wireless printer. I've been unable to find any way to do this. I've been able to use USB to SSH into the R Pi. Linux commands can then be used to search WiFi seen on wlan0, but I haven't found a way to use Linux to then configure for a selected WiFi. The python wifi module also searches WiFi but does not successfully configure the R Pi, and is no longer supported. raspi-config doesn't seem to work, and is anyway too complex for the users I have in mind. I'd appreciate any help.
Update with additional information from a comment:
I want to use the Raspberry Pi to send video over a WIFi router. The Raspberry Pi is completely enclosed. I cannot attach a keyboard or monitor. I do not know which WiFi network I will want to connect to until I have physically moved it to the desired location. Then I have to search for the new WiFi and log in with its password, all without connecting a keyboard or monitor, only using either USB or hot spot. This would be similar to connecting a wireless printer to a WiFi network using a USB connection.