Openfire group chat

I just want to implement group chat like what’s app but confused with openfire.

There is “Group Chat” (Multi user chat) : using this we can create “Temparory” room and multiple users can chat but unable to transter media

so this is useless because of temporary nature and not able to send file.

I can see in admin there one more menu “users/groups” > “Group” : there is create group option. But I don’t know how can i create group using code.

Also I don’t know if it meet my needs

Main requirements are : group chat same as what’s app : text messages and file transfer over group

Many Thanks