Not getting updates to cart?

[AsatruAlliance]

I know I'm sorely in need of updating our cart (very old version), but I'm not able to connect for updates.  Getting a strange error connecting to marketplace as well for extensions.
we're running 1.2.15 currently, and I know I likely have to stage the updates (along with updating PHP at the same time with our web host)
am I missing a connection somewhere? can I force connect/download the update packets somewhere?
sorry for being such a total newbie, it's what happens when volunteers work the small NPO

[Basara]

Hello.
To move forward safely, you’ll want to start by backing up everything. Make sure to back up your database using your hosting panel, such as phpMyAdmin or any database backup tool your host provides. Also, don’t forget to back up your site files through your hosting file manager.

Since you’re currently running version 1.2.15, you’ll need to upgrade in steps. The correct order is: first upgrade to 1.2.16, then to 1.3.0, and finally to 1.3.1. You can find the upgrade packages using their version key (for example, abantecart_upgrade_130) or download them directly from GitHub at this link: https://github.com/abantecart/abantecart-src/releases. Just click Assets at the bottom of each release to download the upgrade package ZIP file.