Before completing these instructions, please make sure to boot into Breakpoint and install Alohomora. These are relatively simple tasks, but I have created a guide just in case, as Breakpoint causes a few frustrating quirks that did take a couple hours to troubleshoot. For these steps, you can have the Breakpoint Guide Website open on your Chromebook.
This is mostly for apps including Google Docs, Google Classroom, and Schoology: any apps that require you to sign-in using a Google Account. However, kiosk apps are coded to not allow pop-up windows as an anti-cheating mechanism. Therefore, you must instead use Alohomora's sign-in page, which redirects you to a webpage instead of a pop-up window.
Open a new Alohomora tab, which should contain all the shortcuts and buttons, as one of them is needed to sign in. Then, click on the "Add Account" icon: the third icon from the right on the top right. The symbol is an illustration of a person with a "+" symbol next to the illustration.
Sign-in to your Google Account normally. I suggest sigining-in to your enterprise/school account first, then repeating this process for your personal accounts.
Due to being run inside a kiosk app, you unfortunately lose the capability to take screenshots normally. However, you can simply use a screenshot extension to achieve the same thing. Many screenshot extensions cease to function inside the Breakpoint browser, but Awesome Screeen Recorder & Screenshot has been found to work.
Install the screenthot extension from the Chrome Web Store, linked here. Once the extension fully installs, pin the extension to your extension bar.
Once the extension installs, click on the extension. To take screenshots, click on "Capture". "Visible Part" will capture the part of the webpage you can see, "Full Page" will capture the ENTIRE webpage, and "Selected Area" will allow you to select a specific area to capture. Click on the method you wish to use, then click "Capture". A tab displaying your image should appear. To save the image to your files, click "Download".
A detailed step-by-step process will be created soon, but the process is quite self-explanatory, so it shouldn't be too hard.