@shama OK, I loaded up a NodeMCU and tested with the API…
it seems you do need to have the letter D with the pin, but NOT as in using the silk screened designations…
So… the silkscreened pin D3 = GPIO pin 0 but you need to write it as D0 in the API URL… does that make sense?
And no quotes or apostrophes around the value… So try this
http://192.168.1.9:8080/80d3631030d247f0b4250eecc2410849/update/D0?value=0
http://192.168.1.9:8080/80d3631030d247f0b4250eecc2410849/update/D0?value=1
And I seem unable to use PWM with direct pin manipulation, so 0 and 1 are the options… just like you want anyhow