which version of iPadOS are you running? Does the pencil appear in the the list of paired Bluetooth devices? Does is appear under Bluetooth devices but you can’t pair it?
Otherwise - if it was paired and disappeared and doesn’t show up under Bluetooth in any form - try:
- make sure that Bluetooth is enabled on your iPad.
- make sure your iPad is charged
- get a piece of wire/single-core cable, ca. 30cm in length
- wrap the cable around the AP2 starting 4 cm from the tip till 2 cm under the top - basically make sure that it’s wrap closely around for the main, center part of the AP2
- hold it for about 2 minutes to the AP2 charging area/side of your iPad. If it was paired in the past, it should automatically reconnect. Otherwise it should show up in the list of Bluetooth devices.
- If the battery of the AP2 was drained, you have to charge he AP2 beforehand by letting it connected on the charging area for e.g. an hour and then try the procedure.
nota bene: use sheathed, unshielded cable like e.g. it is used for bicycle lights, model trains, bread board circuit design; or e.g. sheathed wire used for flower arrangements, etc.