Hint for HELP

i NEED HELP plz , i stuck with the upload shell, i found the creds from port XXXX, and i logged into the main web site and found out that the upload direction would be easier than to get admin by b**** s*** , but i couldn’t upload the shell, btw i read the source code and i tried harder, all the ways that i know to bypass the upload mechanism, any hint for that point plz.