give role when a user add reaction Discord.py

问题:

i'm working on a bot for my discord channel and i'm learning python while doing it and i want to give role when a user adds reaction the code i came up with is this

@client.event
async def on_reaction_add(reaction, user):
    ChID = '487165969903517696'
    if reaction.message != ChID:
        return;
    if user.reaction.emoji == "