The USB charger supports Power Delivery (PD) with an output power of up to 120 W and an output current of 3 A via a USB-A port. However, the HP ProBook, especially models such as the ProBook 450 G8 or 450 G10, is known to be compatible only with certain HP Smart USB-C chargers (usually 45 W or 65 W) and third-party chargers are often not recognised as compatible, which can lead to charging problems.
Since the Xiaomi USB charger only has a USB-A port and the HP ProBook is usually charged via USB-C PD, it is very likely that this charger is not suitable for charging an HP ProBook notebook with USB-C PD. In addition, tests show that HP ProBooks often only charge reliably with HP's own USB-C chargers.
To summarise: The Xiaomi USB charger with 120 W and USB-A port is not compatible for charging an HP ProBook notebook via USB-C PD.
You can use the USB charger with 120 W power for your Xiaomi 15 Ultra. Although the Xiaomi 15 Ultra supports a charging speed of 90 W, the charger is compatible with 120 W and delivers the necessary power without causing problems. The charger has a USB-A port and supports HyperCharge technology, which enables fast and safe charging. So you don't need another charger that has exactly 90 W, as the 120 W charger works without any problems.