I had a bit of a struggle with this, so I thought I would post a how-to.

This works with the V3 datalogger for data retrieval only, no control as yet.
You can also request remote control, which will allow you to manually change settings remotely on the inverter from the web page or the phone app, but there is no automation support as yet.

Thanks to this excellent project: https://github.com/hultenvp/solis-sensor

First steps:

Register with Solis support and raise a ticket for API access.


https://solis-service.solisinverters.com/support/login

select “API access request”

subject API access

Use the email address that is registered with your Solis account

enter the following

Name

Customer ID [6digit number]
plant reference [your plant name]
inverter s/n [16 digit number]
data logger s/n [15 digit number]

You should gain access within a few days, go online and activate it.

https://solis-service.solisinverters.com/support/solutions/articles/44002212561-api-access-soliscloud

(You can also request Remote control access for the app and webpage here )

Once activated, install HACS on Home assistant, and then install the Solis sensor integration.

To connect, you will need the following:

SolisCloud URL, API key, API secret and your inverter ID

In the first screen, enter a name for the inverter (this is just a label for HA)
and the SolisCloud API URL (note there is no slash at the end) and select soliscloud as the portal version.

In the next screen enter your email, the API secret, the API key,and the inverter ID.

To obtain the inverter ID, login to soliscloud and navigate until you see this URL in the top address bar.

https://www.soliscloud.com/#/station/stationdetail_1?id= your 19 digit number

Hit submit, and then you can add Solis settings to the energy dashboard, or configure your own.

Using HA , you can then schedule appliances to run when your solar output peaks and your battery fills up, rather than exporting to the grid, for example.