Go to "Settings" > "Opportunities and Pipelines" > "Pipelines" > click the Trash Bin Icon
Click "Ok" to confirm.
How to Delete All Opportunities in a Pipeline
Before deleting all opportunities in a pipeline, ensure you have backed up any important data. Double-check that no active deals or essential records will be lost during the process. Additionally, communicate with your team to confirm that everyone is aware of the upcoming deletion and has had a chance to save any necessary information.