Understand that the anointing oil is simply a channel for believers today to release their faith in the finished work of Christ. As such, there is no need to obtain any special oil. Normal olive oil can become anointing oil once it has been consecrated, or prayed over and set apart.
As a king and priest in Christ (Revelation 1:6), a "royal priesthood" (1 Peter 2:9), you can pray over the oil and set it apart to be holy. Here’s a prayer you may wish to use for blessing and sanctifying your oil:
"In the name of Jesus, I set this oil apart to be holy anointing oil.
Jesus, I thank You for going to the cross and bearing all our sins on Your own body. This holy anointing oil speaks of the perfection of Your finished work. I thank You that whatever this oil touches, the fullness of Your grace, power and healing virtue will flow.
May it turn darkness into light, lack into abundance, sickness into healing. May it release Your restoration, provision and fruitfulness into every situation.
I pray that wherever this oil is applied, it will bring glory and praise to Your name. Amen."