How can I create an online order form?

I want my restaurant customers to access a order form online. Fill in the quantities and submit the form which will then go to three different email addresses.

Preferably, access to the form should be through a password under their control.

I want to be able to customise the product lines for each customer and amend it readily.

Do you have any facility to do this, and how much does it cost?

You can create one main form and then clone it for each customer separately. Also, you can set a password box for each one. I believe these articles will help you.
Order Form Templates
Send Notifications to Multiple Recipients
How to set a password for my form?
How to Clone an Existing Form from Your Account
Our free accounts are able to get 100 submissions(10 of them is payment) per month. Please check our pricing page.
I am sorry for too many redirections. I will be glad to assist you with specific subjects.