Create index without downtime | TRANSITIONS

I have a requirement to make the transitions feature work faster.
Checking the Matomo FAQ pages, i find that i need to add 3 index.

The challenge is try to add the indexes without downtime, any advice?
I’m using MariaDB 10.4.10.

The tables sizes:


I am no database expert and can’t help with avoiding downtimes this way, but you could try using this to not loose any data during downtimes: