Note Template are pre-defined notes that are use for to fill up the memo and notes of an invoice.
To create or update these, please follow this guide:

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(1) Go to Home > Click on the Settings icon
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(2) Click on the LISTS > Note Templates
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(3) To update the content, click on the category > then tap the overflow menu of the specific note > then choose Edit to change it.
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(4) To add new notes, click on the + icon.
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(5) Then enter the Title, Category and the Content of the notes.
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(6) This will display the new note template entry to the list.

Then to use this on an invoice:

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(1) Open or access an invoice > then click on MEMO
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(2) Then click on the 4 boxes icon.
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(3) Then choose on a specific note template to be used.
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(4) Then click on the Use this.
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(5) Then click on the Save button.
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(6) This will display the notes to the invoice.