The only audio output that TV has is optical digital audio.
The receiver only has analog inputs so you need to get an optical to analog converter https/www.amazon.com/Parts-Express-Digital-Converter-5-1-Compatible/dp/B00CWELGMS/ref=cm_cr_arp_d_product_top?ie=UTF8
plus the cable to connect it to both the TV (toslink optical audio cable) and the receiver (stereo RCA interconnect cable). Any input on the receiver except phono is fine to use.
Check the TV manual on how to turn on the optical output. You may need to turn the TV speakers off and change the audio type in the TV menu.
I assume that you have the speakers connected to the receiver correctly and that's not an issue.