Posts shall not contain only links, which holds even stronger for topic start posts.
Your start post contains only a link but no description. As a result it is not clear what the link is about (without first clicking it) and worse it is unclear why you are posting it, which invites to any random responses - including critical ones - wasting other people’s time and efforts and leading to nothing.
RFM95 is a LoRa radio that itself does not support the LoRaWAN protocol. The LoRaWAN protocol stack software therefore needs to run on the microcontroller. Only few public LoRaWAN compliant libraries are available and they are too large to fit on an ATTiny84 (were not designed for that).
That software is closed source and was developed commercially, investing much time. The source code is not publicly available. The IoT space and LoRaWAN have matured since then and more capable hardware and software solutions are currently publicly available. It is therefore not wise to use ATTiny for development of new LoRaWAN devices.
The TinyLoRa device appears to be able to transmit / send LoRaWAN uplink messages only - which is only a part of the LoRaWAN protocol - and without capabilities to handle downlink (control) messages.
Devices that are able to transmit only are NOT LoRaWAN compliant and are therefore NOT supported on the forum (similar to ‘single-channel’ devices and LoRa-only devices).
My 2¢: The RFM95 module alone is much more expensive than ATTiny84 and many microcontroller(board)s that are more capable than the ATTiny84. Add to that the price of the sensors. So from price perspective I personally do not really understand why to save (less than) €0.75 on a microcontroller(board) and then spend a lot of time and hassle to get LoRaWAN (somewhat) working on ATTiny.
The contents in this thread has moved way off-topic and appears to lead to nothing but discussions, even behavior not tolerated on the forum.
To quote @TwentySixer’s undiplomatic statement
I will now end above discussions.