Kfa, I would look up who is the company's Transfer Agent (it will likely be Compu Share as they are the largest). You can find this on the OTC market site under security details. https://www.otcmarkets.com/stock/NWBO/security shows NWBO's agent.
They can help you. I suspect you will have to send the Transfer Agent your cert, it will then be back in electronic form and you can then transfer to a broker.
The process for handling paper certs is very strict, make sure you understand them and follow exactly.
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