I see, you're on Raspberry Pi?

This is what I would do, forget about the UI in this case.

• Evaluate $UserBaseDirectory in your notebook.
• Using you favorite command-line or file management tool(s), place the desired .m file in the Kernel directory that should exist under $UserBaseDirectory.

Then Get (and FindFile) should see your .m file.

This is essentially what I expect that File > Install... does.

Thanks Joel -- but starting from the left and under the File menu is where I do not see an "Install..." option. Under Palettes there is an "Install Palette...", but no "Install..." under File. I would attach a screen shot, but the Raspberry Pi 400 PrtScn key does not take a screenshot while the pull down is open. However after searching around a bit under the Raspberry Pi group where I entered my question I did find an earlier and similar question, to which someone answered that one should just put the .m file into the FileNameJoin[{$UserBaseDirectory, "Applications"}].directory. I did that and it does seem to do the trick -- at least I can Needs[] the file now (though I'm not sure everything about it is working and I'm not sure if there might be additional things I need to do).

Anyway thanks much for replying...