@anon36505037 thanks for the shout out. I have actually also made an IR garage door opener. Maybe one day i’ll make it available for everyone. Here is a picture of the first prototype: IR Garage Door Opener
RF just means “radio frequency.” There are many different RF frequencies and protocols in use today. Zigbee is RF. Zwave is RF. WiFi is RF. Bluetooth is RF. 344 MHz is RF.
None of these can talk to each other.
You need to know the exact frequency and protocol being used before you can figure out whether it’s possible to find a bridge device to then talk to SmartThings. Which it may not be – – some RF devices use a manufacturer proprietary encoding.
If the user manual doesn’t say what the specific protocol and frequency are, assuming the device is sold in the United States it will have an FCC license number on the device somewhere. It may be on the back, it’s sometimes inside the battery compartment.