Hi @Cherly 

Based on location selection , select Flow Action.

e.g 

1.  Under the Connections related list, create two distinct connection records: one for the US endpoint (and its corresponding US credential) and one for the UK endpoint (and its UK credential). 

2. 

 Open your flow in Flow Designer. Create an input variable (e.g., Region or CountryCode) so you can pass either "US" or "UK" when triggering the flow

3.  Add the out-of-the-box Lookup Connection utility before your REST/Integration step. 

4. Map the Connection Attributes using a data pill. Set the filter/condition dynamically by checking your flow's Region input.

5.  In your REST step, set the Connection option to Use Connection Alias, select your alias, and then drag the Connection pill output from your Lookup Connection step into the Connection field.