Yes, It is very easy in salonist to select multiple payment mode at the time of billing, split the payment
While creating an invoice, when client pays half amount through cash and rest half through any other mode, you can split that half amount check how
On Quicksale (billing page) after adding the client and selecting their services, Adjust the amount under given Adjust Payment Box
Ex. the service amount is 2000 where client is paying 500 through cash and rest remaining amount using Upi gateway
Add 500 under Adjust Payment Box
Now click on Cash and it will instant give you the remaining amount
Now we can see there is 1500 left, So now click on UPI and payment will be cleared, you can generate a bill.
Also, here is the video tutorial for your reference