Possibly similar model manual from manufacturer:

https://www.evenflo.com/on/demandware.static/-/Sites-evenflo-Library/default/dw009a2787/Instruction%20Manuals/25701061%20-%20Chase%20Select%20EN%20Jan17.pdf


Replacement parts from manufacturer:

https://www.evenflo.com/parts-accessories/car-seat/30621633/30621633_parts.html

https://www.evenflo.com/support/instruction-manuals.html


https://www.google.com can be used to search for manuals, but unfortunately, the one I found appears to be a different model.

https://www.manualslib.com/products/Evenflo-Chase-4041185.html

Perhaps you could contact a retail store or internet site that sells that particular model and ask for a copy of the manual.