Can I evict my tenant because I want to sell the property?

Yes, but only at contract expiry and with 12 months' notice served through a Notary Public or registered mail, stating the sale as the reason (Article 25(2)(d)). A WhatsApp, email or verbal request is invalid. The notice generally survives the sale, so the buyer can complete the eviction. Serving less than 12 months makes it defective.