On this page https://www.dell.com/support/manuals/us/en/04/vostro-14-5490-laptop/vostro_5490_setupspecs/left?guid=guid-12cd14bb-8db3-47d7-a090-15d75787517a&lang=en-us :

USB 3.1 Gen 1 (Type-C) port with Power Delivery/DisplayPort

https://www.dell.com/support/manuals/us/en/04/vostro-14-5490-laptop/vostro_5490_setupspecs/ports-and-connectors?guid=guid-29ab3b25-b4d9-4b9a-b1bf-821e8a6a7b8f&lang=en-us mentions power share but not power delivery

read  https://www.dell.com/community/Vostro/Charging-Via-USB-Type-C/td-p/6136052

Unfortunately "Power Delivery" is ambiguous because USB PD can be run in either direction, and some systems only support one direction.  USB PD can be used to charge the system, but it can also be used to allow the system to provide higher than normal power levels to attached peripherals, typically either 7.5W or 15W.  I've seen system that support charging but not USB PD power for peripherals, and others that support USB PD for peripherals but not charging.

On some systems at least for a while, Dell would clearly identify systems that supported USB PD charging by writing something like "supports Power Delivery (system charging/DC-in)", but I've seen multiple cases now where systems had only the spec wording that you found and the system still supported USB PD charging.  Unfortunately, I've also seen reports of other systems that had that wording and only supported providing USB PD.  So unfortunately you might have to either wait for someone who's actually tested this or else just buy a USB PD charger and see what happens, and then return it if it doesn't work.  You won't damage your system by plugging a USB PD charger into it if the system doesn't support it, fyi.

@jphughan, thank you. My friend has PD charger, but i worried, that i can damage laptop, if it does not support PD charging. But if not - i''l try to plug in it. 

@Dactil  It’s fine to test, because USB PD power does not flow until the charger and device perform a negotiation, and if the device doesn’t support USB PD, then it won’t perform that negotiation and therefore the charger will not provide power.

Hello,

Finally, have you tested if the USB Typce-C of Vostro 5490 offers power delivery?

In their manual they said: "One USB 3.1 Gen 1 (Type-C) port with DisplayPort/PowerShare" and in other page they said "USB 3.1 Gen 1 (Type-C) port with Power Delivery/DisplayPort"

Not tested yet. I dont have USB type-c PD charger, but my colegue has. We dont meet because of epidemic situation. I will test it, but later.

I tested it with my macbook air type c charger and it does work (possibly even better than my Dell charger). my concern is that it may damage the battery because it's not a "designated" charging port. does anyone have more info?

Well, I owned a Vostro 5490 since Nov 2019. I had used a 45w power bank to charge the laptop, no problem. Prefer choice is 65w.

Also can use the same port to charge mobile phone.

Finally i tested USB Type-С charging with Xiaomi 65W charger - it works! Charging speed the same as with original Dell charger.