i cant receive any message with sim800l arduino mega

help me im using sim800l and only copy example code from gsm grps library and change tx rx based on my arduino and all clear but i never receive any message , whats going wrong?

whats going wrong?

Clearly, operator error.

Posting a lousy picture of text sucks. Post text AS TEXT!

Post your code IN CODE TAGS.
Post the serial output AS TEXT.