PrintableCal can import tasks from Todoist. Here's how:
Click the Add Calendar button on the Calendar Data Sources step and select the Online -> Todoist option. The Add Calendar Source - Todoist window will appear.
PrintableCal can import from any number of Todoist accounts. To import from a previously added account, select the Use an existing account option and pick the desired account from the drop-down list. Otherwise, select the Add an account option and continue to the next step.
Click the gear button in the upper-right corner and select Settings from the drop-down menu.
On the Settings page, click Integrations.
Copy the next in the API Token field.
Paste the copied text into the API token field on the Add Calendar Data Source - Todoist window.
Click the Next button. PrintableCal will connect to your account and provide a list of your projects. Use the checkboxes to select the projects you'd like to make available to PrintableCal as calendar data sources.
Click the OK button to add your Todoist projects to PrintableCal's list of available calendar sources.