The ornamental design for a kayakanchorbracket, as shown and described.
FIG. 1 is a perspective view of a kayak anchor bracket;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a perspective view thereof as positioned on a kayak.
The broken lines showing a kayak illustrate environment and form no part of the claimed design. Further, the broken lines showing portions of the article form no part of the claimed design.