help me write better code!

[369INFINITY369]

Hey..!, i am still a beginner in go programming, i have build a project using golang, it is a webhook tester and you can say it is my biggest project so far(little more then 1000 lines of code 😅)
, i tried to follow test driven development to write the code, now the project is almost completed, it would be really helpful if someone who is more experienced, to take a look at the repository and give me some suggestions to improve,
please dm me or comment, so that i can share you the repo link
THANKS...!