Fallon has been uploading to YouTube this new version of The Tonight Show amid the COVID-19 pandemic. Fallon's wife, Nancy Juvonen, films him and he begins each episode with an opening monologue.
"The federal government has pushed back a tax deadline by 90 days. I think that's a good idea because trust me, once I run out of toilet paper, the next thing I'm grabbing is a stack of 1040s," Fallon joked.
Garner, during her interview, discussed how her children -- Violet, 14, Seraphina, 11, and Samuel, 8, -- were dealing with having to stay home.
"I think I have the perfect-aged kids for this because they're big enough to understand and to have the conversations. Like, we're built for challenge. We can do this. We're a tough team. Let's learn about a vacuum cleaner," the actress said.
"You know the hard thing are teens and early-20s people and my parents. My parents are the hard ones. I'm like dad, mom the world is shut down to keep you guys safe and they're like 'We think we're going to go to Sam's Warehouse.'"
Garner ended the interview by playing her saxophone which she has nicknamed Sally the Sexy Saxophone. Garner played "Happy Birthday" on the instrument with Fallon changing the lyrics to be about hand washing.
Garner and Fallon prompted charity Save the Children which helps to make sure kids can learn and get the nutrition they need while school is out. Fans can donate to the charity which Garner has partnered with for the #SaveWithStories campaign, alongside Amy Adams.
The #SaveWithStories campaign involves celebrities reading books while asking for donations.