Items containing http POST not working in OH3

Within OH2 I have a lot of items controlling mit Rademacher rollershutters via my homepilot which is located at These iatems are configured like this:

Dimmer rolloBuero "Rollo Buero [%d %%]" <rollershutter> ["Switchable"]     {http=">[*:POST:$s&command=0] <[]"}

The items are controlled from my sitemap using

Slider item=rolloBuero

Whenever I move the slider the rollershutter moves accordingly. Also when I move the rollershutter from my remote control or its wallswitch the items and sliders are updated within seconds.

All this does not work from OH3. There are no errors shown in openhab.log. Eventlog only shows 2 entries:

2021-03-06 19:41:41.131 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'rolloBuero' received command 32
2021-03-06 19:41:50.303 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'rolloBuero' changed from 0 to 32

How can I migrate these items to OH3?

You used the Version 1 http binding. Version 1 bindings are no longer supported!
There is a actual Version http binding available, this one uses things and channels. Read read the documentation.

@opus Thanks for the hint. This is now working with http-binding 3.0.1. For anyone who is interested:

Here is my .things file:

Thing http:url:homepilot "HomePilot" [ baseURL="", refresh=10 ] {
        Type number: Channel_Rollo_Buero "Rollo Büro" [ stateExtension="", stateTransformation="JSONPATH:$.device.position", commandExtension="$s" ]

and my .items file

Number rolloBuero "Rollo Büro [%d %%]" <rollershutter> ["Switchable"] {channel="http:url:homepilot:Channel_Rollo_Buero"}