Add deposit payment on the checkout page

I want a code to insert either in the function.php file or in a sniper to add a deposit to the final form-pay total.
the plugin I use does not use all the features of woocommerce it just uses the form-pay checkout page; Please help.

Rental fee per day                    × 1                       €1,250.00

Security deposit fee (not included) ×   1                       €8,000.00

One way fee                           × 1                       €1,000.00

After hours return fee                × 1                       €300.00

Subtotal:                                                      €10,550.00

Total:                                                          €2,550.00

I want the total to be like this

Total:.....

to pay:.....

Balance :....

Best regard