In your cPanel you should look for an option to edit the PHP settings. There is a file called php.ini which holds all these settings and more.
Not all cPanels allow editing PHP settings. If yours does, then open it an look for a string called:
Change it to whatever you need.
For example, if you change its settings to 128MB then your upload size limit will go up to 128 Megabytes.
Also search for a string called
Change this to the same value you set for the previous setting.
I hope this helps and resolves your issue.
If it does, give me a kid 🙂