Go to the home page and scroll down

you click on my challange which should be in the corner and then scroll down and it should say

How to enter a code is:
1:go to the page my challenge
2:scroll down initial you see the enter code bit

Click on my profile then scroll down. Under your badges should be a place that you can type your codes in.
Hope this helps!

Go to home, then scroll down. You’ll see the badges section. If you scroll down a little bit more, you’ll see a space to put in your cade. Hope it helps!

go to home
scroll down where there are badges and rewards
click on the white rectangle
enter your code
do enter
it will take you to the top
scroll a bit down and click on the thing where it says your reward

hope that helped
bye