{{ "{{Start.call.from" }}}}
in Variable to compare field.
In Operation, select “Is equal to” from the drop-down list.
In the final field, enter a value to compare: in this case a phone number — for example, 1-202-555-1234.
{{ "{{Start.call.from_iso2" }}}}
in Variable to compare field.
In Operation, select “Is equal to” from the drop-down list.
In the final field, enter a value to compare: in this case the ISO code for the country you want to block.