If you are in scale plan or above then you can enable the offline payment checkout. 
Go to Settings > Configure Chargebee > Billing LogiQ > Offline payment methods > click 'Enable'. On enabling, configure the offline payment methods which you intend to support.

Offline payment methods supported in Chargebee are:

• Bank transfer
• Cash
• Check
• ACH credit transfer
• SEPA credit transfer

Note: Invoices can be generated for offline payments across all plans (by manually recording payment). Offline Checkout Abandoned cart: This feature is currently available on selective plans. Please refer to Chargebee plans and pricing page. If you are on our previous plans, then this feature is available on Scale and above plans.