Conditionally show signature field (SF)

I am using Adobe Sign for Salesforce and I am trying to conditionally show a signature field based on a condition involving a field from the merge mapping. The logic is, if the condition is met, it will show a digital signature field, else, show the standard signature field.

Example:

{{digsig1_es_:signer1:digitalsignature:showif(SfMergeFieldSample="Show this")}}

{{Sig_es_:signer1:signature:showif(SfMergeFieldSample!="Show this instead")}}

Does anyone know what is the correct syntax for this? Also, in case I want to use the In/Not in condition, how do I declare a comparison value with space?

ex. option?="Value 1, Value 2, Value 3"

I also tried this condition but it seem to not work.

https://helpx.adobe.com/sign/using/text-tag.html