Liturgical practice means to publicly worship aspecific regional religion. So the liturgical practice of African Methodist would be just that, Africans expressing in this case Christianity publicly to the church. I don't know of any specific instances so you would have to look that up.
African Methodist Episcopal University was created in 1995.
Metropolitan African Methodist Episcopal Church was created in 1838.
St. John African Methodist Episcopal Church was created in 1865.
Olive Chapel African Methodist Episcopal Church was created in 1896.
St. Joseph's African Methodist Episcopal Church was created in 1891.
Mother African Methodist Episcopal Zion Church was created in 1796.
Lomax African Methodist Episcopal Zion Church was created in 1894.
Mount Vernon African Methodist Episcopal Church was created in 1921.
St. Luke African Methodist Episcopal Church was created in 1910.
First African Methodist Episcopal Church of Los Angeles was created in 1872.
Goler Memorial African Methodist Episcopal Zion Church was created in 1918.
Old Ship African Methodist Episcopal Zion Church was created in 1918.