@manuelc1318 as I wrote, you can transmit data in both directions: write to a characteristic to send data from client to server, and either read from a characteristic or use notifications for data from server to client.
@letsgo If you have a home router & access point, the easiest is to have both LoPys connected to that. For that, follow the instructions at https://docs.pycom.io/chapter/tutorials/all/wlan.html, section: Connecting to a router.
if you want to connect them directly, one of them has to run as access point (AP), the other as station (STA). Since the devices run as AP by default, you just have to reconfigure one of them the way, told above.