As your home instance is Lemmygrad, I shall tell you how to add your pronouns on that instance.
Go to your account settings, and under “display name” type the name you wish to be known as, followed by your pronouns in brackets or parentheses. There is a character limit for display names, however, so if you use many different pronoun sets, you may need to choose just one or two for your display name, and include the rest in your bio.
On my own main instance, Hexbear, there is a separate field for pronouns in the settings, a drop-down menu above the display name. This feature seems to be unique to Hexbear, however.