Request [solved]

I have came across a coin that was issued in the 13th-14th century and I would like to add the person and the coin he issued, into the Catalogue. 

Issuer was Amadeus Aba (also Aba Amadé) he was a Hungarian oligarch in the Kingdom of Hungary who ruled de facto independently the northern and north-eastern counties of the kingdom (today parts of Hungary, Slovakia and Ukraine). He held the office of Palatine (nádor) several times (1288–1289, 1290–1291, 1291–1293, 1295–1296, 1297–1298, 1299–1300, 1302–1310), and he was also judge royal (országbíró) twice (1283–1285, 1289).

And I would like to ask if it would be possible for me to add him or atleast if could I ask someone to add him.

You can add the coin yourself, without specifying the ruler, with the link at the bottom of every coin search result.

A coin is missing in the catalog? Add it yourself!

Having the coin listed gives greater incentive to add the ruler. When you do list the coin it would be helpful to, provide a link to this topic in the comments in addition to any other supporting information.

It would be useful to read the guidelines first.

As mentioned by bjherbison, you can add the coin yourself. 

Until the coin is submitted, or a reference is provided to a coin made under the authority of Aba Amade, there is nothing more to be done (I could not find an example of a coin on acsearch).