I am not able to add 10 digit mobile number

[Kal_Lam]

This post discussed previously should help you solve your issue:

How to limit my id number entry to 10 characters?

Hi @PamelaLlanes, Try using the regex code regex(., '^[0-9]{10}$') with the question type as text. A similar example has already been discussed in the forum: To learn more on regex please feel free to visit our support article Restricting text responses with regular expressions. Have a great day!

To learn more on regex, feel free to go through our support article Restricting Text Responses With Regular Expressions. It has a lot of practical examples that should be useful.