How do I upload an image to Pixton?

Hello there, I'm curious about uploading an image to Pixton. Could you please guide me through the process step-by-step? I'm not very familiar with the platform and I'm having a bit of trouble figuring it out. Is there a specific button or menu I should be looking for? Also, are there any restrictions on the file size or format of the image I'm trying to upload? I'd really appreciate your help with this. Thank you in advance!