The ABA English certificate is issued by the American & British Academy and endorses the knowledge acquired from our English course. It indicates the level you have passed, the linguistic skills acquired based on the Common European Framework of Reference for Languages (CEFR) and the date obtained. Therefore, it is valid as proof of your level of English and although it refers to the "European Framework", this is one of the main criteria used all over the world.
If you are wondering whether it is official or not, bear in mind that no certificate is official in itself. In order to determine whether a certificate is official or not, public institutions must list it as such. The issue is some certificates are seen as more prestigious than others and are used more often in order to justify language level, but these vary depending on the authority requesting justification for linguistic skills and it is them who decide which certificate is valid for their institution.
Your certificate will be available on your account if you have a Premium subscription and have completed 100% of the exercises from a particular level. You can download it from your Campus (web) from the menu on the left-hand side, by clicking on the certificate icon. You can also download it from the app, by going to your account, tapping on the user icon and then on the certificates option.