So you have set up an application & registered the device, right?
When creating the App TTN will have auto generated an APP EUI. Have you used the manage EUI’s settings to add the one for your device to the available list and then selected that from the list for the device registration? (Example: As I highlighted to another user on this post Dragino LSN50 help - #12 by cslorabox) Does the Join Req you see in GW console data show your APP EUI as also shown in that linked example? Have you double checked the typing in of all the keys you listed?