It is troublesome to add ink directly to the original ink cartridge. If you are not careful, you may burn the ink cartridge. If you are not strong in manual skills, it is recommended to change the ink cartridge.
If it is an Epson printer, it can be changed to a continuous supply.
If it is a Canon printer, it is recommended to change it to easy-to-refill ink cartridges. There are no connecting lines and no modifications to the printer. The performance is more stable and the machine warranty will not be affected.