Implementation of MiMC over Edward curve I'm trying to use MiMC-hash function [1] over Edwards curve, in order acheive an hash function that output a point on Edwards curve.

However, in Section 5.1 ([1]), they state that $gcd(3,p-1)=1$, which is not valid the value $l$ (the order of the base point).

Is there any trick that I can use to achieve that? 
(I was thinking about working on smaller field, but I struggle to put the result on the correct point on the elliptic curve).

Thanks.

[1] - https://eprint.iacr.org/2016/492.pdf
Using the MiMC-hash function won't actually give you a hash function that outputs a point on the Edwards curve. The MiMC-hash function is based on a sponge-construction that uses the MiMC-permutation internally and is configurable for any $l$-bit output. It is designed for applications that profit from a low number of multiplications such as multi-party computation, zero-knowledge proof systems or SNARKs.

It seems you just want a hash function that takes an arbitrary input and outputs a point on a specific curve. In that case and depending on your specific requirements you could look the "try-and-increment" method described in section 3.3 here or at the methods described in this work.