Table with dynamic filter

Hey! I’m trying to build a table with filters using a repeating group and a group, I get the data through the API connector. Please help me implement the logic so that in the Group element in the body of the API Connect call, the constituent parameters are substituted depending on the values ​​in the drop-down list. If values ​​are selected in Dropdown :
[
{
param1:[dropdown value]
}
]
If no values ​​are selected: