I have a roku stick 4k , dont know where or how to get the wireless receiver cord for set up.
Assuming you have the 3810/3811 Streaming Stick, your Roku will not work without that specific power cable, which has the wireless receiver built into it. You can purchase a replacement from Roku here. Of course, that is $20, and for $25 you can get a brand new 4K Streaming Stick, which might be an improved version of the one you have, again depending on your Roku model. Plus, you can probably walk into a Best Buy or other retailer that sells Roku and get one today, instead of ordering the cable and waiting for it to arrive.
Assuming you have the 3810/3811 Streaming Stick, your Roku will not work without that specific power cable, which has the wireless receiver built into it. You can purchase a replacement from Roku here. Of course, that is $20, and for $25 you can get a brand new 4K Streaming Stick, which might be an improved version of the one you have, again depending on your Roku model. Plus, you can probably walk into a Best Buy or other retailer that sells Roku and get one today, instead of ordering the cable and waiting for it to arrive.
how do I purchase just the cable ?
There's a link to the purchase page in my previous post.
You can't purchase the cable separately if you have 3820/3821 Streaming stick 4k. The 3810 wireless receiver linked won't work on the newer models. The older 3810 has a USB b-mini input, where the newer Sticks have a micro USB jack. They are just not compatible