Threshold for Evaluation object detector

Hi Guys

I would like if possible how to make this Threshold for Evaluation and validation of created R-CNN object Detector, i tried to make it in the attached scripts but it does not work, I want to make Threshold for score that like below 0.58 that score and bboxes should not be appeared

Herein the code:-

load('gTruth.mat')
output = selectLabels(gTruth,'signal');
if ~isfolder(fullfile('EvaluationData'))
    
    mkdir EvaluationData
    addpath('EvaluationData');
    
    evaluationData = objectDetectorTrainingData(gTruth,...
    'SamplingFactor',1,'WriteLocation','EvaluationData');
end
imds = imageDatastore(fullfile('EvaluationData'));
numImages = height(evaluationData);
result(numImages,:) = struct('Boxes',[],'Scores',[]);
for i = 1:numImages
    
    % Read Image
    I = readimage(imds,i); 
    
    % Detect the object of interest
   [bboxes, scores] = detect(detector,I,'MiniBatchSize', 32);    
    % Store result 
    result(i).Boxes = bboxes;
    result(i).Scores = scores;
   
end
% Convert structure to table
results = struct2table(result);
overlap = 0.1;
% Evaluate Metrics
[ap,recall,precision] = evaluateDetectionPrecision(results...
    ,evaluationData(:,2),overlap);
[am,fppi,missRate] = evaluateDetectionMissRate(results,evaluationData(:,2),overlap)