This is possible to do with DigiSigner. To achieve this you need to add your text not directly to your document, but populate a text field with it.
For example, you need to send a quote to your customer but expect that the number of items and the amount may change.
In this case, you can change the text by clicking on the text field you want to update on the document and entering your values in the Prefill field for signer box on the right pane. Lastly, click on the Done orange button at the top right of the page.
We also recommend marking your text field as Read only to lock it. In this case, the signer won't be able to change your values. In fact, they will look to them as regular pieces of text, not as fields with content that can be edited.
This is how the same page looks from the signer's end as shown on the Address field.
After editing the text, you don't need to resend the document. To view the updated version, the signer can use the same link you sent to them before. If you still want to resend it, you can do so by clicking on the signer's email address under the document's name and selecting Resend Document > Resend Document.
After opening your document once again the signer will see the updated version.
Please note that after the document has been submitted by the signer, you won't be able to change the text fields' values anymore.