Start blynk client at boot up?

i am trying to get blynk client to run at start up / reboot all the other posts are very old and i have tried them with no luck, has this been solved ? can someone point me in the right direction please . basically i want my blynk client to run when raspberry pi b4 boots into desktop . it works fine if i run from terminal…

pi@gempi:~ $ blynk-client auth code here

i have looked up how to run a command on boot up but all i get is running a .py or a script dont even know how to make a .py from the command i type to get my blynk running , and its blynk client not blynk server …please help