You can charge a booking fee to your clients in a few different ways, depending on how you accept payments and pay out your providers.
Set up a provider revenue split
If your shop is cash only, and you also pay your providers in cash, you can set up Resurva to track a revenue split for a provider, so that a percentage of the provider's revenue will be marked for the business instead of the provider.
For example, you could increase the costs on your widget by 10%, and set up a revenue split that says the provider gets 90%, so that the shop keeps that 10% markup as the booking fee. Then, you can export this data before every pay period to see how much you should pay each of your providers. In the screenshot below, the provider is set up with a 90% revenue split, which means they'll receive 90% of their earnings, and the shop (location) will keep the other 10%.
Increase the cost of your services
Something else you could do is increase the cost of your services by a specific amount, like $3, and count how many services were booked within a pay period using the booking search. Then, you can take the $3 fee for every booking (by multiplying the fee by the amount of bookings, and keeping that amount for the shop) and pay the rest to the providers.
Charge a fee for online payments
If your shop accepts online payments, you could also set a tax rate on your widget to increase all of your service costs by a certain percentage, and when you pay out your providers, you can subtract the tax rate to keep as a booking fee. When clients are selecting a service on the widget, they'll see the cost without the tax applied, and they'll be shown the full cost (with tax included) at the end, when they enter their card details to finalize the booking.