What is AC(activation code)

Activation code is a string provided by the operator to activate your profile, defined in SGP.22.
It starts with LPA:1$ or 1$ and contains SM-DP_ADDRESS and MATCHING_ID, which are separated by $.

Here are some examples of Activation Code:

LPA:1$<SM-DP_ADDRESS>$<MATCHING_ID>
LPA:1$SMDP.GSMA.COM$04386-AGYFT-A74Y8-3F815

1$<SM-DP_ADDRESS>$<MATCHING_ID>
1$SMDP.GSMA.COM$04386-AGYFT-A74Y8-3F815

How to get AC(activation code)

If the carrier provides a QR code, the content of the QR code is your activation code, you can use a QR code scanner to read it.
Some carriers will provide the SM-DP address and matching ID along with the QR code, or just give you AC, you can assemble them into an AC link yourself.
Some carriers may also require a confirmation code to download your profile, codes may be sent separately.