Hello graphics designers in the house, please I need help on the applications used in making cartoon video animation like that of House of Ajebo.
Searched for it on YouTube, but not getting a tangible result please help me

Sir, Those guy really spent time on that stuff, you can only create yours with the use of applications because no app is ready made

Go to reallusion store and purchased CrazyTalk animator software that is use to create comics and animation video. If you don't have money go for the free trial for a month. NOTE you must have a Core i5 or core i7, 8gb Ram or Above and the system must have GTX or RTX 900 series or above Nvidia Graphics Card

I've watched some of thier videos.

You will need to learn Adobe Illustrator. Illustrator is to help you develop your characters, environments, and other objects in the scenes.

Then, you will need to learn Adobe After Effect or Adobe Character Animator. Either of them will help you animate the things you drew in illustrator. There are many tutorials on YouTube for them.

I must tell you, they are not something you can learn within a short time. So, you must be really determined to learn them. You should be relatively okay animating some stuffs within 6 months, IF YOU HAVE BEEN SERIOUS WITH YOUR LEARNING.