Lifetime of blob url limit

i 'am building a blog website ,where the user can comment with an image ,so for that i'am trying to upload a local image and save it into database (postgres)
for that i used URL.createObjectURL to create a url blob for the image and i save that url to database , and i was thinking that the lifetime of the url unlimited but i was wrong because when i refresh the page an error appears net::ERR_FILE_NOT_FOUND it says that the url not found in the database ,so how i can let the url always available , or if this way not good show me the good practice.