The Gordon's Trinkets receipt reflects the killer's purchase of the necklace. Look at the date and time listed on the receipt. What was Ezra doing at that date and time?

Look at the Dating App Evidence.

The Dating App Evidence shows Ezra was messaging a woman (Marisa) around the same time the necklace was purchased at Gordon's Trinkets. Where was Ezra when he was messaging Marisa?

When Ezra and Marisa "match" they are less than 0.1 miles away from each other, and they begin messaging each other immediately. So, if we can figure out where Marisa was when she was messaging Ezra, we can figure out where Ezra was (within 0.1 miles).

Ezra suggests meeting up at Giovanni's (a pizza place) which is "right across the street" from Marisa. Where is Giovanni's? There's a piece of evidence that lists Giovanni's address.

The back of the Seattle Times magazine has an ad for Giovanni's that lists its location as 27 Melrose Street. Gordon's Trinkets is located at 29 Melrose Street (as indicated on the Gordon's Trinkets receipt).

The Gordon's Trinkets receipt shows the necklace was purchased at 2:16pm on September 9th, 2019. Ezra is messaging Marisa between 2:17pm to 2:19pm on September 9th, 2019.

Based on the Dating App evidence and the Seattle Times magazine, we can infer that Ezra was near Gordon's Trinkets when the necklace was purchased and had the opportunity to purchase it.