If yes, in simple terms, you set your budget and you try to bid yourself for the work. Then the customer chooses you, if you are convincing enough for them to take you.
You gotta start a timer and let the customer know that you are charging. Once you have done with your work, and the customer is happy, you may stop the timer and the timer works in steps of 15 minutes.
Then the customer leaves you a feedback and you will be credited with the amount agreed. I guess the payout duration will be about three to five days later in order to curb fraudulent accounts and you can request your pay once you reach a certain threshold.
The way you described it, it does sound similar to Upwork? Out of curiosity - are you a mentor on the platform or have past experience with this?
Set your rates higher than you would think you need to. You need to offset the amount of calls where you waste your time up front and the job goes nowhere (usually the first 15 minutes or so are unbilled while you explore the problem description).
It can be pretty good. You do need to build the skill of discovering which jobs aren't worth taking though.