Well, the OP’s issue is RB750 doesn’t run back to home (BTH). It does run WG, so a “manual” process may be possible if one side has a static IP. But @normis is right, being able to “convert” a RouterOS login into a WG client in a couple taps in an app is pretty handy.
But if you have static IP, it really should just be a multi-step process as described in docs or @anav’s WG compendium post.
FWIW there was a recent discussion on the RB750 vs. hAPaxLite (later of which does support BTH) here if the OP wanted to swap routers:
http://forum.mikrotik.com/t/hap-ax-lite-vs-hex-750gr3/171771/1