I don't wan't to collaborate pages document I wan't to send as an enclosure

Yes. You can follow the next paragraph and send a Pages document to an email recipient who makes modifications to that attachment in the same version of Pages and then returns it to you in the same manner as you sent it. Each of you will have Pages version information stored locally, and that could adversely impact any benefit of full document version recovery if needed.

When you click the Share toolbar item in Pages, it defaults to Send Copy, not Collaborate. If you want to email a Pages document as an attachment, then select Mail from the Send Copy list. If you want to send a different document format (e.g. .docx, pdf, etc), then you select the Export and Send… menu item. From the Export panel, you pick the document type and then click the Send a Copy button to attach it to Mail or other options on that menu.

The advantage of document collaboration is that it ensures all collaborators are using the same current version of Pages and prevents others from some editorial measures in the document.

I am uncertain how you got that dialog as you would have to have access to iCloud Drive if the document were already there, and if the document is on your Mac, then my preceding instructions should not invoke any need to open iCloud Drive or even involve collaboration.

You are welcome.