These are collectible cards added to GTA Online with the Diamond Casino & Resort Update. They are scattered throughout San Andreas, and for collecting them you receive casino chips, RP, and other rewards.
Radio Antennas are a collectible in GTA Online, added with the Cayo Perico Heist update. They are installed throughout San Andreas, their locations are shown on the map below.
Some antennas are located on rooftops. All of them can be reached on foot, but it’s better to use a helicopter or other suitable aircraft.
To repair an antenna, walk up to it and press the action button — “Right” on the D-Pad on the controller or “E” on the keyboard by default.
You can repair the antennas in any order. Each repaired antenna brings money and 1000 RP. For the first antenna, you will get GTA$10,000. For each subsequent antenna, this amount will increase by GTA$2500. The last antenna is an exception, and for its repair, you will get GTA$70,000. In total, you will receive GTA$250,000 and 10,000 RP.
When Still Slipping Los Santos is released across San Andreas, Joy Orbison should be in touch with an additional reward.