Help is this cancer ?

Hi there. My 9 year old Chihuahua developed this lump about a year ago. It started out very small and it’s just gotten larger and larger. She doesn’t seem to be in pain, but she does seem a little bit more tired, but she is older now a lot of Google images said that because it was pointy and lumpy like that that it was cancerous but ChatGPT said it just looks like a lymphoma. What do you think it is and how serious is it?