How to disable copy paste in text field

Hi @Grzesiek2010
As you know, i did ask you a procedure to send random number to respondent mobile number automatically,so interview could not know which random number send to respondents mobile number, but in your solution random number shown in interviewer's message application.

so i want to restrict interviewer to copy random number from its own device to ODK Collect.

basically i want to verify that mobile number provided by respondent is OK..

BR, Nouman