On my 1099 NEC how do i link my schedule C

in box 1 of the NEC there should be a line to link to schedule C

double click on the blank space and either you can create a new one (enter profession) or a list of existing schedule c's will pop up with the option to create a newone.

Thanks for the reply Mike, when I enter one that pops up or enter a new one it still returns and says turbotax will not electronically file and that I need to fix it.