How to add or change Document Status

Hi, everyone,
As you can see in the image i have only 3 document status, i want to add custom documents status similar to my workflow, so how can i do that.
Please share steps.

Thank You

doc status has 3 states only.
You can modify the Status field states according to your necessity.

There is no option to add or remove status, if there is any please share the path , Thank You