Assalamu alaykum, My question is that can you ask Allah anything like due'a, you can ask Allah any dua you want right like, o allah make me smart, or give me beauty, will Allah except this dua , please let me know insha allah assalamu alaykum

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

There are some etiquettes for supplication that should be observed, and a person is not totally free to ask whatever he wants without restrictions, rather it is forbidden to exceed the limits when supplicating. It is reported that 'Abdullaah Ibn Mughaffal narrated: "I heard the Prophet saying: ''There will be people among this (Muslim) nation who would exceed the limits in ritual purification and in supplication." [Ahmad and Abu Daawood]

Exceeding the limits when supplicating is, for example, when one supplicates for something which contradicts the wisdom of Allaah in creating people with a certain share of beauty that could be less than others. Ibn Taymiyyah said: 'To exceed the limits when supplicating is to ask for what one is not permitted to ask for, like supplicating for help in forbidden matters, or when supplicating for something which Allaah  has willed not to do, like asking Him to make one live until the Day of Judgement, or to make him stand free of basic necessities of human beings like food and drink, or to ask Allaah to show him the unseen, or to make him infallible, or to bless him with children without being married, and other forms supplications that exceed the limits, and which Allaah does not like, and does not like the person who supplicates with them.'

Therefore, the supplication that is mentioned in the question, despite being among things that Allaah is able to grant, it is a kind of exceeding the limits as Allaah created the creation in this universe according to certain constant Divine laws, among which is the impossibility of changing the form of a person from ugly to handsome for instance. Therefore, one should not ask Allaah something that is contradictory to these universal laws set by Allaah.

Nonetheless, a person may ask Allaah to improve his manners and make him accepted by people and make his moral conduct better than his outside appearance, as this is something that is within the realm of possibility and reason.  As a matter of fact, this supplication is better for the person than having a good outside appearance which conceal an evil inner self.  

Allaah Knows best.