tried to set a range of port forwarding (16124-16128) and I receive the message that" This range should be between 1 and 65535"

I inserted an individual number and it was accepted

Left the internal port blank, but I kept receiving either the message invalid format or this range should be between 1 and 65535

I also tried using "," (comma) between the numbers along with words "to" and "and"  but nothing worked :(  

unfortunately the automatic support wasnt helpful that is why i am reaching out here for HEEELPPP
thank you in advance