Short answer: yes
it just cant be my own art made unless youve commissioned me in particular with the express intent of it to be made for merchandise which influences more in how to make the design and the colors for printing

Also that, i dont mind if people just use said artwork to get a stand or stickers of just for THEMSELVES only, buyers can make merch for themselves and i encourage it because who doesnt enjoy having keepsakes of their characters around in a physical medium