If you don't want to spend money, when uploading your work, you will be asked to add a topic in the publishing interface, which is the pound symbol button. After the pound sign, you can enter the topic you want to add to get the traffic of that topic.
When we add topics, we will only add topics in the same field as our own works. According to your video, Tik Tok officials will preliminarily analyze the topics of your video and give several reference topics, such as # motorcycle in the above picture, because there is a motorcycle helmet in the video. Or for example, if your work is music, then your topic can be music. When you enter the word music, a drop-down menu will appear, and all topics related to music will appear, and the usage of the topics will be marked, so that you can know which topics are used the most, and you can choose the one that is used the most. Adding a topic in the same field can make Tik Tok quickly identify the field you want to touch, and it will recommend your work to users who like this topic. When we usually brush videos, careful friends will find that when you like videos on a certain topic, Tik Tok will recommend works on the same topic to you one after another. As long as you add this topic when you publish your work, you can get the flow of this topic.