SQL Query with variable name table in Stored Procedure using MySql 8 version

Hi,

This is my SQL query that working correctly and it's stored an a database MySql version 8.0.17

(I'm sorry but if I'm paste the query code the question is not posted... does anyone know why?)

I've tried using this SQL query on an a Stored Procedure on this mode

(I'm sorry but if I'm paste the stored procedure code the question is not posted... does anyone know why?)

But I've this error

Procedure execution failed 1146 - Table 'db_test.',tablename,'' doesn't exist Time: 0,138s

I've tried with this question without success

Any help would greatly appreciate... Thank you.