I want to make: whenever the player right clicks my custom block with leaves, it will fill with water (like a cauldron)

I searched around for hours and hours on various tutorials and still cannot figure it out.

Tick rate is 1, block entity and fluid storage is enabled, trigger is on block right clicked

I want to make it so that: whenever the player right clicks my custom block with leaves, the block will fill with actual water and can be collected by the player (similar to a cauldron). Also removes 1 leaves from player inventory. Everything works so far except filling of the block with water. Does this part have to be under the procedure 'On tick update' instead of 'On block right clicked'? Do I have to use blockstates? 

Procedure
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