Driving the LED from your I/O port pin limits you to the maximum current such a pin can source or sink, which for the UnoR4 Wifi I believe is 8mA. Remote controls typically drive their LEDs with hundreds of milliamps. So what you do is use the I/O pin to drive a transistor, which will have a gain of 100 or more. This link shows you how to set up the transistor:
https://arduino.stackexchange.com/questions/36758/using-a-transistor-to-get-100ma-on-a-ir-led
That's 3.3V. For 5V the 18-ohm resistor would need to be a higher value, something like 33 ohms, or maybe 47.
I'm finalizing both the raw receiver sketch and a raw transmitter sketch, neither of which requires a library, which I will post on Github But they will both be only for 328P Arduinos.