Alchemy.Permissions.channel_permissions

You're seeing just the function channel_permissions, go back to Alchemy.Permissions module for more information.
Link to this function

channel_permissions(member, guild, channel_id)

Gets the actual permissions of a member in a guild channel.

This will error if the channel_id passed isn't in the guild. This will mismatch if the wrong structs are passed, or if the guild doesn't have a channel field.