magento2 – Magento 2 – Check of readiness fails when checking the dependency of components

I have the Magento 2.2 community. installed on managed VPS (Hetzner).
I'm trying to install a component and, before installation, it starts "Checking the readiness".
All departures except for:

Check the dependence of the components

We found conflicting component dependencies. Hide details

For additional assistance, see the component dependency help.

I have no details about the error.

What I've tried

I've followed the instructions from here:

I was performing the installation of a module through dialing and, when asked for an authorization (public and private keys), I recorded them in compose. json.
As this is one of the possible reasons listed in their documentation (composer.json change), all he says is to "edit composer.json" but that does not say how or what …
I have opened composer.json but I have not found any key …

I appreciate the help with that 🙂