Variable Reward in points (Specific Case)

I don’t think I explained myself well with the previous post, this is the situation I wanted to achieve:
Scenario: I have a gamified buddyboss platform complete with gamipress.

Game mechanics: users earn experience points for each action they take in the forums and groups (10xp for each action)

Every so often (every 3 or 5 posts) they earn coins.

So….., there is no way to:

1- make it so that instead of actions always giving 10xp, they have a variable reward within a range?

2- make the number of actions to reward with coins variable?

3-make the number of coins variable?

I am open to looking for alternative programming ways or solutions to achieve this.

thank you