DistroKid does not assign IPI numbers. An IPI number (previously referred to as a CAE number) is an international identification number assigned to songwriters and publishers by their Performing Rights Organization to uniquely identify them as rights holders. 

Your IPI number is available in the repertories of ASCAP, BMI, SESAC, and any other PROs. They can be found by searching for your name in their respective repertory searches on their websites. 

Adding an IPI in DistroKid Credits

If you have an IPI number, you can add it in the songwriter credits for your release at https://distrokid.com/credits. Once there, add the songwriter credit and then click "Does this songwriter belong to a Performance Rights Organization (P.R.O.)?" From there, you can select the PRO and enter the IPI number before saving the credit and sending the updated metadata to services.