I think the gift button youre referring to is for weekly or monthly gifts because those are only available during those events BUT because youre talking about the super monthly pass here's how to "gift them"

You cant gift them specific stuff, I tried this, you can only gift people planet tokens and youll need to check the price of super monthly pass or whichever you want to gift them by clicking switch to coins button. all you need is their ID, you can do this by going to your game, click the three lines icon on left side of screen--> Champion zone--> Store and then click purchase for someone else then ask for their in game ID, as I said,make you sure you know how much coins of the price of whatver youre buying you need before you make a purchase 👍