Two different jobs, two different exports. One gets a project into a spreadsheet. The other gets everything you have out of the app.
Export a project
From a project, export the spec as CSV or as JSON.
CSV is the one to use when somebody wants it in Excel or Google Sheets: a row per item with the identity fields, quantity, unit of measure, status, and the money, plus the section it belongs to. Lenders, accountants, and estimators all want this one.
JSON is the one to use when something else is going to read it. It keeps the structure, so sections stay nested rather than being flattened into a repeated column.
What the export contains
The same fence applies as everywhere else, with one important exception: this is your own data, so a project export you run for yourself includes your internal cost and markup fields.
That means a project CSV is not a file to forward to a client. If you need something client safe, send the share link or a PDF.
Export your whole account
Settings has an Export your data section. That produces everything: your projects, sections, items, products, folders, and templates.
Use it for your own backup, for moving to another tool, or before you close the account. It is rate limited to a few runs an hour because it is a heavy operation, not because we would rather you did not.
What it is not
An export is a snapshot, not a sync. Nothing you change in the exported file comes back into the app, and there is no import path that reads an export back in.
Deleting your account
Deleting your account is in Settings, at the bottom, and it is permanent. Export first. Once the data is gone it is gone, including every share link, trade package, and home manual link you have sent, all of which stop resolving.