ID of the button, later passed to the service message
OptionalcountMaximum number of peers to be selected
OptionalnameWhether to request the name of the peer
Peer type, along with filters
OptionalphotoWhether to request the photo of the peer
OptionalstyleStyle of the button
Text of the button
ReadonlytypeOptionalusernameWhether to request the username of the peer
A button requesting the user to choose a peer (reply keyboards only)