Sort:  

Click on rewards box below your post when you post and change to 50/50. Unfortunately it can't be changed once you post, but you can use it on future posts.

What of the third option that says no payment

That declines payment for the post. People can still upvote it, but when it reaches 7 days you get 0. When you see posts with a line through the payout value, that's why. It means they declined payment on the post.

Wow i just learnt something new. Thanks
Never knew what that 50/50 meant and the two others. Thanks for teaching me what i will teach others