For this achievement, you need to collect all new Scrolls and Trinkets, which were obtainable at the start of the Sunbreak expansion.
It's also necessary, you've already unlocked the "Sturdy Padlock" Achievement from the Basegame.
New added monsters like Golden Rathian and Silver Rathalos are not required for this achievement.
You need the following Scrolls:
Daimyo Hermitaur Scroll
Blood Orange Bishaten Scroll
Aurora Somnacanth Scroll
Scorned Magnamalo Scroll
Garangolm Scroll
Shogun Ceanataur Scroll
Magma Almudron Scroll
Lunagaron Scroll
Astalos Scroll
Espinas Scroll
Gore Magala Scroll
Seregios Scroll
Pyre Rakna-Kadaki Scroll
Malzeno Scroll
Shagaru Magala Scroll
Furious Rajang Scroll
The Archdemon Scroll
You get them for killing each Monster 10 times. Trap and catch them doesn't count!
List of Trinkets from Lottery Jackpots
Kingdom Longship
Cohootrioshka
Toy Spelunker
Regalfin Pouch
Gowngoat Bobble
Massive Copal
Gargolda Statue (only obtainable after you took a picture of Gargolda)
Espinas Statue
Malzeno Statue
Archfiend Statue
Shogun Ceanataur Statue (random drop from the Lottery, this is what most players are missing)
Just hit the Jackpot, when one of them is the special price.
Lottery Tickets increase the chance of getting them
List of Trinkets from Relic Records
Daimyo Hermitaur Statue - 5 Jungle Relic Records
Astalos Statue - 10 Jungle Relic Records
Garangolm Statue - 5 Citadel Relic Records
Lunagaron Statue - 10 Citadel Relic Records