Dumb Jinja question

I know I'm missing something that's probably incredibly obvious, but here goes.  I am trying to combine static and dynamic text in a pipeline field, a field name and some text.

I didn't expect my first guess to work, {{a.field_name}}_Text, but the other things I tried didn't work either.  I'm sure one of you has the answer.

Thank you in advance.

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Paul Peterson
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