The difference between a problem solved in one email and a problem solved in five is what you put in the first one.
The two attachments that solve most things
The System report. Go to Mollie Payments, then the System tab, and click Run checks. Copy the report and paste it in.
It shows us your WordPress version, your PHP version, your Houzez version, your plugin version, your mode, your license state, whether the webhook is configured, and which payment methods are actually live at Mollie versus which you have enabled in the plugin.
Your API keys are deliberately left out, so it is safe to send.
The logs, if the problem is a payment. Go to the Logs tab, switch on Enable debug logging, reproduce the problem, then click Download .txt.
Sensitive data is redacted before anything is written, so the file is safe to send too.
Switch logging off again afterwards.
What to write
What you did. The steps, in order.
What you expected.
What happened instead. Word for word, if there was a message.
That sounds obvious. It is remarkable how often we get “it does not work”, which we cannot do anything with.
What helps enormously
A screenshot. Especially of an error, a checkout that looks wrong, or a setting you are unsure about. One picture regularly saves three emails.
The transaction, if there is one. The customer’s email address is enough for us to find it.
Whether it ever worked. “It stopped working on Tuesday” is a completely different investigation from “it never worked”. Tell us which.
What changed. A plugin update, a theme update, a host migration, a new security plugin. If something changed just before it broke, that is almost certainly your answer, and it is the first thing we would ask.
What not to send
Never send your API key. Not to us, not to anyone. We do not need it, we will never ask for it, and anyone who does ask is not us.
If you have already emailed it to someone, go to your Mollie dashboard and generate a new one right now. It takes a minute, and it makes the old key worthless.