I'm finding this info on Nigerian adoption pretty useful and interesting:
https://binti.com/adoption/international/nigeria/

The number of Nigerian adoptions has been going up every year!

This is the list from that page of the Nigerian adoption requirements, if its helpful:

Residency: Individuals wanting a Nigeria adoption must be citizens of Nigeria. Americans may adopt, but they must have a dual citizenship in order to adopt from Nigeria. Prospective adoptive parents must also have the child they want to adopt in their home (in Nigeria) for a period of several months to several years before they will be able to obtain an adoption in Nigeria.

Age: Parents must be a minimum of 21 years older than the child they want to adopt. They also must be at least 25 years old to be eligible for an adoption in Nigeria.

Marriage: Married couples must both adopt and they also must both be Nigerian citizens. Single individuals may only adopt children of the same sex unless there is an exclusion granted by the Nigerian court.

Family Size: There is no standard set limiting the size of family couples or individuals seeking an adoption in Nigeria.

Income: Prospective adoptive parents must prove they are financially stable and able to care for additional children throughout the Nigeria adoption process.

Education: No education limit has been set for a Nigeria adoption.

Health: Though the adoption process in Nigeria does not set a health standard, it is assumed applicants will have a health report in their home study certifying that their health is sufficient to raise adopted children.

Criminal: Though the adoption process in Nigeria does not set a criminal standard, it is assumed applicants who have criminal histories will have an explanation and a certified disposition by the court in their home study.

Other: Currently, Nigerian law does not prohibit homosexual couples and individuals from adopting from Nigeria, but there is a bill proposing such a law. In general, those known to be gay or lesbian may not obtain a Nigeria adoption.