The Function channel.set_permissions()
sets the permissions of a user in the channel.So you need to provide a target as the first argument.For example:
await ticket_channel.set_permissions(ctx.message.author, send_messages=True, read_messages=True, add_reactions=True, embed_links=True, attach_files=True, read_message_history=True, external_emojis=True, manage_channels=True)
I think what you are looking to do is restrict the channel to members with specific roles assigned to them.
for that you might want to read this documentation
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