First find out where on the phone they really live, because the answer picks your route. Open the phone's Contacts app, and in its settings look at accounts or contact storage: most Android contacts belong to the signed in Google account, some sit in device storage or a SIM.

Google account contacts, the common case, never touch the phone at all: on the PC open contacts.google.com, sign in with the phone's account, Export, choose Outlook CSV and import that file through Outlook's Import/Export wizard into Contacts. The phone was only ever a window onto the Google copy.

Device stored contacts need the phone itself: in the Contacts app use Settings, Export or Import/Export, Export to storage, producing a single .vcf holding everything. Move it to the PC by USB, email or cloud drive. In Outlook do not run the vcf through the import wizard, which reads only the first contact of a multi contact file, instead drag the vcf from Explorer straight onto the Contacts list in the People view, which processes every entry.

Mixed storage, export both ways and let the CSV import's duplicate handling or a quick File As sort clean the overlap. Four hundred contacts land in minutes by either path once the storage question is answered.