Not sure why no one has mentioned this solution anywhere, but it's soo simple. Go to developer options, and simply enable "force allow apps on external", that's it. Don't know why people like to overcomplicate things.
I’m not sure that it is so simple. On some phones, the option might not be available; or on some phones, if toggled, it wouldn’t work; or you might need to root first; or you might need this or that version of the OS.
Even if successful, it might be unworthwhile: when I did it years ago, the phone ran slow, and the icons of apps stored on the SD card would sometimes disappear.
No, it's not that simple. Only certain devices from certain manufacturers running certain versions of Android will have this option. Which one are you referring to? (FYI, my Lenovo Tab M8 FHD running Android 10 does not have this Developer Option.)
Maybe you could also include a link for the thread you're trying to respond to?