Entering this is a two-step process. The PIN is composed of two parts, the prefix and the suffix. Use at least 4 numbers for each half of the PIN.
PIN example: 10101-1971
After entering the prefix, two words will be generated and displayed on the device. These are known as your anti-phishing words. The same two words are supposed to appear each time you enter the prefix. The purpose of these words is checking that the Coldcard has not been compromised and is safe for you to use before entering in the rest of the PIN.
Enter the PIN prefix;
Write down the two anti-phishing words;
Enter the Suffix (second half of your PIN);
Confirm your PIN Prefix and Suffix.