HI Benzig,
To control external equipment like your Line 6 you need to create a "Midi Control Track". Check out this video which I found really useful.
https://youtu.be/CAPB4-kI1GE?si=ThyHOtpei6_WnZHc
You can also do it with a midi track but you may find problems with getting the change events exactly where you want them.
John B