How can I repopulate a matrix field on a front-end form?
Using the example above, here is how you can re-populate the given matrix field(s). The below is assuming only one matrix field is visible by default [0]. Depending on your use case, you may need to dynamically generate the index number.

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{%- if entry is defined %} value="{{ entry.myMatrixFieldHandle[0].fieldHandle }}"{% endif -%}
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