I'll go along with Chaosmagnet - a belt holster would be best. Some ideas here: https://www.galls.com/defense-spray-holders

For my two cents... having done years of training with Corrections and street officers, you've got to have your 'tools' such as pepper spray, set up for access the same place, the same way at all times. Pocket carry can work but you need a dedicated pocket - sew a part of the front pants pocket closed so it is a correct size to hold the canister properly. You can get pants (like 511) that can have a dedicated pocket for pepper spray too.

If you are using one of the small key chain size - it needs to be secured somehow so it is always in the same position. You might be able to find a holder at a sporting goods store used for flashlights that could work too. Good luck!