The number of copies of the e-Visa approval letter you need to print out can vary depending on the specific requirements of the country you are visiting. In general, it is recommended to print at least one copy of the e-Visa approval letter for your own reference and to present it to immigration authorities when entering the country.
However, it is always a good idea to check the instructions provided by the issuing authority or the official e-Visa website for the country you are visiting. They may specify whether you need to print multiple copies or if a digital copy displayed on a mobile device is acceptable.
Additionally, it's a good practice to keep a digital copy of the e-Visa approval letter saved on your mobile device or accessible through email, just in case you misplace or lose the printed copy. This way, you can present the digital copy if needed.
Remember to comply with the guidelines provided by the e-Visa issuing authority to ensure a smooth entry into the country.