Client registernumber input from phone

Hi guys, I need to create an extension that allows a user to enter his customer number and record it or send it by email, do you have any solution on how to do it? Thank you

https://docs.asterisk.org/Latest_API/API_Documentation/Dialplan_Applications/ReadExten/

ok but i dont know where create this…you help me pls??

This is definitely dated material but should get you in to the neighborhood.
http://asteriskdocs.org/en/2nd_Edition/asterisk-book-html-chunk/asterisk-CHP-5.html
Use the link that @dicko provided as well as other pages on that wiki to get newer information such as options and to check if any dialplan functions have been removed or replaced.

Other reading as it relates to using custom dialplan with FreePBX can be found here

Note this is also in need of updating because things like macros have gone away.

may be more helpful too for things like dialplan writing but will be less helpful for FreePBX integration.

This can be done enirely with the dynamic routes module, either with one dynroute or by chaining a few together. Further reading:
https://community.freepbx.org/tag/dynroutes