Hello friend, if you want to increase the Page Authority and Domain Authority of your website. So you have to have some patience for that.
Talking about the domain authority, if your website is 1 to 2 years old or even more then you do not need to worry. Google will give it a big DA by ranking it itself.
But if you want to increase DA and PA quickly, then you have to create a backlink for this. This backlink should be from a good domain authority website. Whose spam score should be between 1 and 5. You can increase your DA and PA by making backlinks from them.