You can't give xp to anyone and if it's added, it can be abused. People could make alts to get more xp.
In anni, Players earn exp by killing players, mining nexus, or win the game. To let players earn xp to get their kit, and to make the game balanced. If xp giving is added, the game will be unbalanced. It would pretty much ruin the concept of the rarity which still plays a very big role in Guildcraft Annihilation. Some games don't want to add economy giving system, so players earn their money for their own will, to make the game more enjoyable. If this was added, all(maybe) of the kit price will be changed. making all kit price might be 50k, 100k, or something else.
Don't even think about it, it would ruin Anni forever, players will abuse it in diff ways. You can't give/send xp.
If this is added, they would have an alt afk and it would get xp from nexus mines and victories and send the xp to their main.