How can I remind myself to lock a rental bicycle at the end of the ride? In city where I live, shared bicycles have a wheel lock, which is unlocked by a mobile app what starts the rental period and which has to be locked manually by pushing the lever back to locked position to end the rental.

It already happened to me twice that if there was something or someone distracting my attention when I was putting the bike onto its stand and taking my backpack, I forgot to lock the bike and the rental period continued running.

What habit (maybe purely in my mind or maybe even accompanied by a physical token?) can I develop which will effectively and early remind me about the forgotten operation of locking the rental bike at the end of the ride?

(More information about this particular bike sharing.)
Counting Method

Count the number of steps you must perform at the end of the ride and then refuse to leave the bicycle until you have done all the steps.
For example - End Of Ride Steps:


Park the bike
Lock the bike
Get the backpack


That's three steps.
When you are ready to leave the parked bike you have three things you must do. Don't leave the bike until you have done the three things.

Acronym Method

Create an acronym of the different things you need to do at the end of the ride and refuse to leave the bike until each letter is identified.