Yes. You'll need to use a special form for that situation and fill it out by hand. The form is here: https://cdn.ritaohio.com/Media/700826/Form10A.pdf
Note that your employer must certify that you worked outside the city. Milford is a "RITA city". So, you apply to RITA for a refund.
You don't say where you live. If you are subject to a residence city income tax, you cannot claim both a refund and a credit for the Milford tax paid.
Your state of Ohio income tax is the same, regardless of what city your work in.