1. Select 
Groups
2. Select the group you would like to add a GIF in
3. Select the text field box that reads Post to this group
4. Select the GIF icon 
and add a GIF
1. Tap 
Communities
2. Select the group you would like to add a GIF in
3. Tap 
4. Tap the GIF icon 
and add your GIF
1. Tap Communities
2. Select the group you would like to add a GIF in
3. Tap
4. Tap the GIF icon and add your GIF