I had an upper eye lift 11 days ago. Can I put cocoa butter or vitamin e on the scar?

I strongly encourage you to discuss your plan with your surgeon who has examined you, who knows you, and knows how you are healing.  Do not take advice from strangers who have not examined you.  Generally these measures do nothing that time would not accomplish.  If harm is caused, it is your surgeon who will need to fix the problem.  Call your surgeon and get advice from them.

treatment of eyes after blepharoplastySwelling, discoloration, and some bruising are
to be expected. It is not unusual to have some difficulty seeing during the
first day or two after surgery because of the swelling and eye
lubricants/ointment used during and after surgery.

Patients vary a great deal in their recovery
rate, but usually can resume normal light activity or work 3–4 days after
surgery, using dark glasses and make-up to camouflage the swelling and
discoloration. The patient will usually be presentable without dark glasses in
10 days. A small amount of residual swelling persists for many weeks, but
gradually disappearsYou should discuss any medications with your surgeon