The signup form on their website did not have a non-binary option, so I had to select myAGAB instead.
2019 fall, Elliot Bailey, “Fashion Fluid”, inInsight Magazine[1], volume13, number 1, Reno, Nev.:University of Nevada, Reno,→OCLC, page39, column 1:
Since I came out to myself, I felt myself stop dressing in the way I thought I was "supposed" to dress based on my assigned gender at birth (AGAB).[…] It can still be scary to dress in a way that doesn't match what I was taught based on myAGAB, but it's also really empowering to embrace who I truly am and share it with everyone.
Genderfluid people can question themselves, worrying that they're "supposed to transition" or that they're "regressing" if they present as theirAGAB, or that they're a fraud if one of their gender forms happens to be theirAGAB. Accepting genderfluidity, however, means accepting how many forms one's gender can take.
YourAGAB is the gender that you were assigned at birth based on what your doctor and parents decided you were due to the shape of your genitals.[…] The termtransgender[…] was originally used for people who are transitioning to a presentation different from the one associated with theirAGAB. It is used more broadly now to refer to people who do not identify with their gender assigned at birth, whether they were assigned male and know that they are female, assigned female and know their gender to be fluid and flowing, or any combination thereof.
sex assignment on Wikipedia.Wikipedia