Valkyrie, along with most of the other prominent women in the Cinematic Universe, comes to Carol's aid in the final fight against Thanos.
Valcarol first gained a following after the release of the Captain Marvel film as many fan joked/speculated that two should meet while Carol was off in space. The ship started to get much more attention after Brie Larson and Tessa Thompson started retweeting fanart, as well as publicly tweeting about it at each other with positive messages.
There was some tension between Valcarol shippers and Thor/Carol shippers in the lead up to Endgame after a scene was released showing Thor say "I like this one" to Carol. However, a full on ship war never happened and many Valcarol shippers choose to show Thor as being the person who introduced them to each other.
On AO3, the Valcarol ship is the fourth most written ship for Carol and the third most written ship for Valkyrie. It's also the sixth most written ship in the Captain Marvel (2019) tag.
|SHIPS||het||BobbiFitz • Brutasha • Clintasha • FitzSimmons • Fosterson • Huntingbird • Iron Widow • JessLuke • Kitscliffe • MayWard • NebulaRhodey • PeggySous • Philinda • Romanogers • Scarlet America • Spider Witch • Static Quake • Steggy • Winter Widow • Thunderwar • YoYoMack|
|slash||Capsicoul • FitzHunter • FitzMack • FitzWard • Hawksilver • Iron Husbands • IronStrange • Iron Winter • JackDaniels • Roquill • SamBucky • SamSteve • Science Boyfriends • Spiderlad • Stackie • Stony • Stucky • T'Chalcon • Thunder Science • ThunderShield|
|femslash||Cartinelli • Danbeau • Scarlet Widow • Simmorse • Valcarol|
|non-binary||FrostHawk • FrostIron • Frostmaster • Lokane • Scarlet Vision • Valki|
|family||Domestic Avengers • Iron Dad|
|CHARACTERS||m/f||Bucky Barnes • Natasha Romanoff • Steve Rogers • Tony Stark|