So the main valid methods would be image-based. The guide should focus on generating images with the desired font from online tools.
Also, note that when creating text images, it's important to have a clear background and font color contrast, and maybe add effects like shadows for readability on VK's interface. deia font vk
Legal part: remind users to use free fonts licensed for commercial use, or to check licensing agreements, especially if the content has commercial intent. So the main valid methods would be image-based
Advanced techniques might include using custom HTML/CSS if the user has a VK blog or page, but standard profiles probably can't. So maybe that section is minimal here. note that when creating text images
body font-family: 'Deia', sans-serif;