Only a guild's leader can accept join requests to their private guild. To do this, press the icon with the people's silhouettes in the Guild section and head over to Requests. There you'll see a list of all the requests sent to the guild by players.
Keep in mind, that there can be a maximum of 20 unanswered requests. Once this limit is reached, players won't be able to send requests to join your guild.
Keep in mind, that there can be a maximum of 20 unanswered requests. Once this limit is reached, players won't be able to send requests to join your guild.