1. If it's a collage you've just finished, tap the "Done" button --> choose "Copy Link" --> Paste the link to wherever you want!
2. And if it's a collage from profile / explore, tap into the collage you want --> tap on the share icon on the upper right side (for Android users, the share icon is at the bottom left corner of the collage) --> choose "Copy Share Link" --> Paste the link to wherever you want!
Please refer to the tutorial collage below.