How are extraterrestrial anchor chips inserted in the first place? Does that require abduction of the person?

This is done through abduction most of the time. There can be instances where a site visit is conducted for this purpose as well. Keep in mind that extraterrestrial beings can come and go at will at any hour of the day or night by moving interdimensionally through walls or ceilings, and have people not notice this is happening by switching them off, which is done commonly to prevent any eyewitnesses to what transpires, as well as manipulating the target individual or individuals in the cases where multiple family members, for example, may need to be worked on. For something of this kind, it can be done in the field, so this is a simple matter to arrange because this can be done in a very rapid in-and-out operation that takes place without being seen and leaves no traces behind. There will be no memory either of any other outside manipulation or presence of the extraterrestrials or their energies. It leaves the damage in its wake, which will be ongoing and cumulative because of the consequences for the victim, but it can start very simply and with no fanfare.