This is the error I am getting when trying to install Gmaps by Reinos on EE4.
I'm getting a similar error when trying to install the Gmaps Data Plugin on EE4 as well.
You need to change a little in code at line 230 in upd.gmaps
of your plugin directory.
'constraint' => '255' to 'constraint' => '191'
This need to change from 255 to 191 because there is INNODB utf8mb4
.