The challenge you will have is a wall charger gets so heavy it falls out of the socket at the slightest nudge, so you’re probably looking at a desktop charger.
20+45=65W so you’re ideally looking at 65W. You may be able to get by with a little less but that’s more trial’n’error.
Anker sells this 60W charger which is a wall charger, so given you’re going to connect it to a hub you need to be in a physical situation the power won’t get knocked. What I would do ensure also you get a good warranty support, further down if it does not work, is email support@anker.com with a precise question. Something like “if I use this charger with this hub with this laptop, will the laptop charge?” then if you buy it and it doesn’t you built your argument for a return.
Your laptop has 3 USB-C ports so I’m wondering if TWO chargers might work, one to power hub, one to power laptop?