Entering Phone Number on OLO while ordering food. ( Requested by United Standard POS #73497 )

I tested on out test Online Stores and tried to place an order using 9 digits or more than 10 digits of mobile number and it did let me place the order successfully. However, it doesn't allow if used any special characters in between numbers like a period(.). As requested by the customer if allowing special characters to separate digits or just applying a limit on them, that it can not be less than or more than 10, would maybe serve their issue.