How to upgrade to the new Power and Hosting Packs 2023?

The upgrade to the newest version of the Power/Hosting Pack is available via the standard upgrade wizard in Partner Central:

Upgrades an existing Key with the upgrade plan defined in the method call

Method: partner10.upgradeKey

For PowerPack:

<?xml version="1.0" encoding="UTF-8"?>
<methodCall>
<methodName>partner10.upgradeKey</methodName>
<params>
<param>
<value>
<struct>
<member>
<name>login</name>
<value>
<string>{{API_LOGIN}}</string>
</value>
</member>
<member>
<name>password</name>
<value>
<string>{{API_PASS}}</string>
</value>
</member>
</struct>
</value>
</param>
<param>
<value>
<string>EXT.12345678.0000</string>
</value>
</param>
<param>
<value>
<string>PLESK-12-POWER-PACK-2020-TO-PLESK-12-POWER-PACK-M</string>
</value>
</param>
</params>
</methodCall>

For Hosting Pack:

<?xml version="1.0" encoding="UTF-8"?>
<methodCall>
<methodName>partner10.upgradeKey</methodName>
<params>
<param>
<value>
<struct>
<member>
<name>login</name>
<value>
<string>{{API_LOGIN}}</string>
</value>
</member>
<member>
<name>password</name>
<value>
<string>{{API_PASS}}</string>
</value>
</member>
</struct>
</value>
</param>
<param>
<value>
<string>EXT.12345678.0000</string>
</value>
</param>
<param>
<value>
<string>ADD-PLESK-HOSTING-PACK-2020-TO-ADD-PLESK-HOSTING-PACK-M</string>
</value>
</param>
</params>
</methodCall>

You can use below command to modify license Key using Partner API 3.0
As reference: documentation

For Power Pack:

PUT /30/keys/<KEY_ID_OR_ACTIVATION_CODE>

{
"items": [
{
"item": "ADD-PLESK-POWER-PACK-1M"
}
]
}

For Hosting Pack:

PUT /30/keys/<KEY_ID_OR_ACTIVATION_CODE>

{
"items": [
{
"item": "ADD-PLESK-HOSTING-PACK-1M
}
]
}