How to keep a "My Passport" Drive unlocked

I expect this has been asked multiple times but, after entering ones unlock password, how does one stop ones “My Passport” USB drive from going offline during a backup? It can be half-way through but, if nothing else is running, Windows 10 goes to sleep and the backup quietly fails.

Please refer to the following KBA:

Many thanks but you have answered a completely different question, which I didn’t ask.