You do not have to use AI for every step. Use your own work wherever you like, and let the AI do the rest.
Add my own bonus:
On step 3, click Add my own bonus at the top. Type its title and format (Checklist, Guide, Templates and so on), and a line on what it is if you like. It joins your other bonuses with its own value and cover.
My own outline:
On a bonus that has no outline yet, click My own outline. Type or paste it: one section per line, and the points of a section under it, each starting with a dash. Then click Write this bonus to let the AI write from your outline, or paste the finished bonus.
Paste my finished bonus:
On any bonus that is not written yet, click Paste my finished bonus and paste the whole thing (Ctrl+V) from Word, Google Docs, a web page or plain text. Headings, lists, bold and tables are kept; colours and fonts follow your bonus, so it looks like the rest. Plain text works too: lines starting with # become headings, lines starting with a dash become a list, and **words** become bold. The headings become the contents page of the PDF.
Afterwards:
A pasted or self-written bonus works like any other: Read and edit, Save as PDF, covers, the download page and the bonus page.