Movie of (2?) kids trying to find their missing archaeologist/spy? parents

Trying to remember the name of a movie where two kids go searching for their missing parents. The parents were either archaeologists, or spies, or both. They had given the kids pendants that become important somehow later in the movie.
I don’t remember if the parents left on a mission, or if they were kidnapped.
The opening scene of the movie was old gray city buildings and text showed up stating “London, 1885”. Then a narrator says “In this time of greed and avarice,” or “in this age of greed and avarice,.
I watched it in 2019, but it could have been several years old at that time. Also saw it on an Internet connected TV (Roku) but not sure if I saw it on Netflix or Prime, or where.
Thanks for any help!