@tspycher
AFAIK: this are very simple transmitter/receiver modules. No protocol, no encryption, no guarantee for transmit/receive the correct data. You have to make your own protocol and data integrity functions.
Try to send something out from UART (not faster than 10kbps) and receive it on the other side. Be aware that disturbance could be possible as 433.92MHz is used in a wide range of applications like wireless thermometers, garage door opener, car keys, wireless doorbells, wireless power switches...
As you get the raw pulses out of the receiver it should be possible to receive and decode data from e.g. the thermometer oder switches. There are several protocol descriptions in the web.
If you want to send simple data from one to the other device, ESPnow could be the better option.